2015 FORD F750 clutch

more quickly. If you force the gearshift lever into position, this action
defeats the purpose of the synchronizer by causing gear clash.
Shifting with a Non-Synchronized Transmission
SeeClutch brakeandDouble clutch proceduresin theClutchsection
of this chapter.
Clutch
Do not ride or slip the clutch as this causes unnecessary heat and wear.
Maintain the specified clutch adjustment to prolong its life and regularly
inspect the clutch control linkage for tightness. See theScheduled
Maintenancechapter for other maintenance information. When
adjustment of the clutch is necessary, it is very important that the work
be performed properly or early clutch failure may result and a costly
clutch overhaul may become necessary. Only a qualified technician
should perform clutch work.
Note:Continued use of a damaged or worn clutch, prolonged clutch
slippage or downshifting at excessive speeds can result in a failure of the
engine, transmission or clutch components.
Note:To avoid premature clutch wear and failure, do not drive with
your foot resting on the clutch pedal or use it to hold your vehicle at a
standstill on an upgrade as when waiting for a traffic light.
Engaging the Clutch
•Always start in the proper gear. An empty vehicle can start in a
higher gear than a fully loaded vehicle. Starting in too high a gear can
cause clutch slippage and excessive heat and wear on the clutch. A
gear that starts the vehicle moving at idle speed is the correct gear. If
you have to rev the engine to get your vehicle going, the gear
selection is too high.
•Do not shift until your vehicle has reached the proper speed.
Upshifting before your vehicle has reached the proper speed can
cause clutch slippage and excessive heat and wear on the clutch.
•Never hold a vehicle on a grade with the clutch. This causes the
clutch to slip and can actually burn up the clutch.
•Never coast with the clutch disengaged. The high RPM (sometimes
over 10000) can actually burst the facing material of the clutch.
•Never engage the clutch while coasting. Re-engaging the clutch after
coasting may not only cause a great shock to the clutch, but the
whole drivetrain. Internal engine damage or clutch and flywheel
failure can result from this.
Transmission123
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
Canadian_French(fr_can)

If the transmission is equipped with a ceramic clutch, you must start
your vehicle moving in first gear and engage the clutch before pressing
the accelerator at idle. In addition, do not try to slip the clutch by raising
engine RPM and riding or feathering the clutch pedal since this causes
erratic engagement that can cause engine stalling and potential serious
damage to driveline components.
Clutch Brake (Non-Synchronized Transmissions) - Vehicle
Stationary
A clutch brake stops transmission input shaft rotation so you can
accomplish the initial first gear or reverse gear selection when your
vehicle is stationary and the engine is at idle speed. Clutch brake
application occurs in the last 1 inch (25 millimeters) of clutch pedal
travel.
When using the clutch brake, fully press the clutch pedal and shift the
transmission into first gear or reverse. If the transmission does not go
into one of these gears, slowly release the clutch pedal while applying
light pressure on the transmission shift lever until it shifts into gear.
Note:After engagement of first gear, do not use the clutch brake for
upshifting or downshifting. If you do, clutch brake life shortens and gear
selection shift efforts may increase.
Double-Clutch Procedures - Non-Synchronized Transmissions
In order to properly upshift or downshift:
1. Press the clutch pedal to disengage the clutch.
2. Shift the transmission into neutral.
3. Release the clutch pedal.
If upshifting, wait until the engine speed matches the transmission speed
of the gear you are selecting.
If downshifting, accelerate the engine until the engine speed matches the
input speed of the gear you are selecting. Press the clutch pedal
immediately and shift into the desired gear, then release the clutch
pedal.
124Transmission
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
Canadian_French(fr_can)

the gear teeth. This may damage the PTO unit and the transmission PTO
drive gear teeth, resulting in further damage to the transmission and
PTO.
PTO Operation with Vehicle Stationary
WARNING:When the PTO is operated with the vehicle
stationary, the transmission must be placed in positionNwith the
parking brake set. If the transmission is not in positionNand is
equipped with a remote throttle control, an increase in engine speed
can overpower the parking brake and cause the vehicle to move,
possibly resulting in personal injury and/or property damage.
Stop your vehicle, idle the engine and set the parking brake. Make sure
the gear selector is in any forward drive range, and then engage the
PTO. After engaging the PTO, move the range selector to positionN.
Increase the engine speed until reaching the desired PTO operation
speed. To disengage the PTO after operation with your vehicle standing,
release the throttle, allow the drive equipment to come to a stop, and
then disengage the PTO.
PTO Operation while Vehicle Is Moving
After engaging the PTO for driven vehicle operation, shift to the desired
range and drive your vehicle. The speed of the PTO, during this period
of operation, always maintains direct relation to vehicle speed. PTO
speed decreases in relation to vehicle (transmission output) speed as
shifts to a higher gear occur. When operating the PTO while your vehicle
is moving, the PTO may be disengaged whenever it is no longer required.
When there is no load on the PTO gear, you can pull it out of
engagement.
Vehicles Equipped with an Allison 3000 Series Automatic
Transmission
The PTO drive gear is engine-driven and provides direct engine power.
You can operate the PTO when your vehicle is either stationary or
moving. The PTO gear is in constant mesh with the drive gear in the
torque converter housing. A friction clutch or constant drive transmits
power to the PTO.
Vehicles Equipped with a Manual Transmission
Transmission-mounted PTO units are available for local installation on
your vehicle. See yourBody Builder’s Layout Bookfor restrictions on
use and installation of PTO units.
Transmission133
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
Canadian_French(fr_can)

To engage the PTO unit, stop your vehicle, place the transmission in
positionN.Press the clutch, and allow the gears to stop rotating, and
then engage the PTO unit. You can also select the PTO with the
transmission in gear as long as the clutch is pressed.
When operating the PTO with your vehicle stationary, first set the
parking brake (chock the wheels if your vehicle is on a hill or another
uneven surface).
REAR AXLES
Gross Axle Weight
WARNING:Exceeding these ratings by overloading can cause
component failure resulting in property damage, personal injury
or death.
Your truck has gross axle weight, gross vehicle weight and gross
combination weight ratings. Do not exceed these ratings.
Locking or Limited-Slip Differentials
WARNING:If both wheels are not raised off the ground, the one
wheel that is not raised may pull the vehicle off its support,
possibly resulting in personal injury
If your vehicle is equipped with a locking or limited-slip differential, note
the following:
•Power is transmitted to the opposite wheel should one of the wheels
begin to slip.
•Both wheels must be raised off the ground should it be necessary to
operate one wheel with your vehicle stationary.
Driver-controlled Differential Lock
Note:Never use the differential lock at vehicle speeds above 25 mph
(40 km/h).
Some drive axles have a driver-controlled differential lock. The
differential lock can lock or unlock the differential when your vehicle is
moving or stopped. When extra traction is required, the differential lock
provides full power to both axles.
When you lock the differential, your vehicle’s turning radius increases
(under-steer).
134Transmission
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
Canadian_French(fr_can)

We do not recommend, or approve, performing axle conversions.
However, we understand that, on occasion, others install aftermarket
add-on axles on the truck chassis that allow operator control for weight
transfer from other axles (such as air lift axles).
TWO-SPEED REAR AXLE (IF EQUIPPED)
WARNING:Never shift a two-speed axle when descending a
steep grade as this may cause loss of vehicle control and result in
personal injury.
Note:Do not shift between ranges when the speed control is on.
A two-speed rear axle allows the
driver to select a low range for
greater pulling power and a high
range for greater road speed and
fuel economy. You can also use
these ranges to provide extra steps
between transmission shifts when
driving on steep grades or fuel
economy may be factors.
Axle Shifting with a Manual Transmission
To downshift, select the next lower gear, release and press the
accelerator pedal rapidly, or while holding the accelerator pedal down,
release and engage the clutch rapidly.Note:Use the clutch method
when driving at slower speeds.
To upshift, keep the accelerator pedal down, select the next higher gear,
release the accelerator and pause until the axle upshifts.Note:
De-clutch for smoother axle upshifts when driving at slower speeds.
Axle Shifting with an Automatic Transmission
Note:You cannot split-shift with an automatic transmission. In addition,
downshifting above 40 mph (64 km/h) may result in transmission or axle
damage.
Note:Do not shift the axle to LOW with your vehicle is moving.
Use LOW when you drive a fully loaded vehicle on a severe grade or in
congested traffic. Press the upper portion of the switch.
Use HIGH for all normal driving conditions with a lightly loaded or
partially loaded vehicle. Press the lower portion of the switch.
2SPD
LOW
HIGH
136Transmission
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
Canadian_French(fr_can)

To shift the axle from LOW to HIGH with your vehicle stopped, place the
transmission in positionN,then press the lower part of the switch.
To shift the axle from LOW to HIGH with your vehicle moving, accelerate
to approximately 35 mph (56 km/h), press the lower part of the switch
while the transmission is in positionN,then release and apply the
accelerator.
To shift the axle from HIGH to LOW with the vehicle stopped, place the
transmission in positionN,then press the upper part of the switch.
Split-shifting (Combined Axle and Transmission Shift) (Manual
Transmission Only)
To downshift the axle to a slower ratio and shift the transmission, shift
the transmission and move the switch to the lower ratio before the
clutch is re-engaged.
To upshift the axle and shift the transmission, move the switch to a
faster ratio and make the transmission shift in the usual manner.
Split-shift Sequence
Ratio combination 1234567891011
Transmission gear 1st 1st 2nd 2nd 3rd 3rd 4th 4th 5th 6th 6th
Axle range LO HI LO HI LO HI LO HI LO LO HI
Ratio Extender Use
Low end:You can use a two-speed axle as a ratio-extender when
split-shifting is not necessary. For low end use, just shift the axle into
LOW to start out, and shift to HIGH when you longer need the extra
torque.
Transmission (5-speed) 1st 1st 2nd 3rd 4th 5th 6th
Two-speed axle Axle low Axle high
High end:To use the two-speed axle as a high-end ratio-extender, stay
in the LOW range for normal upshifts and only shift the axle to HIGH on
the freeway for greater road speed.
Transmission (5-speed) 1st 2nd 3rd 4th 5th 6th
Two-speed axle Low for gradeability Axle high
Transmission137
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
Canadian_French(fr_can)

A switch on the instrument panel,
in combination with the accelerator
and clutch pedal, allows the
operator to make maximum use of
the exhaust brake in the following
conditions:
•Off-highway driving
•Mountain driving
•Heavy traffic
•High-speed highway driving.
To switch the brake on, push the switch up. Push the switch down to
turn it off.
While approaching a steep grade, make sure that the exhaust brake
switch is in the on position. The exhaust brake begins working as soon as
you remove your foot from the accelerator pedal.
Before descending a hill or steep grade, always select the proper gear. If
you take the transmission out of gear while descending, it is possible that
you cannot select another gear because of maximum governed RPM.
Make sure the engine speed does not exceed the maximum allowable
engine RPM. Exceeding the maximum allowable engine RPM can result
in damage to the engine. Apply the service brakes to reduce the engine
RPM or make a slower descent by using a lower gear.
While going down the grade, use a low enough gear to descend safely
with a minimum application of the service brakes. As a general guideline,
use the same gear as you use to ascend the hill.
Exhaust Brake Operating Characteristics
The exhaust brake turns on when you remove your feet from both the
accelerator and clutch pedals and the exhaust brake switch is in the on
position. The following conditions exist if the brake is operating properly:
•A slight change in engine sound when the exhaust brake turns on.
•A smooth braking effect. Do not expect a retarding effect similar to
sudden, hard application of the service brakes.
•The retarding force possibly felt acting against your body during
brake application (depending on the grade and vehicle load). This
force is actually preventing the vehicle from going much faster.
•Engine temperature remaining in the normal operating range.
•The tachometer showing a drop in engine RPM (depending on grade
and vehicle load) during a descent.
Brakes143
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
Canadian_French(fr_can)

Note:Read and understand the following steps and perform them
whenever you prepare to drive the vehicle.
Note:The parking brake does not disengage unless sufficient system air
pressure is available.
If your vehicle is equipped with a dash-mounted push button (Allison
3000 Series) or steering column-mounted (Allison 2200 and 2500) gear
selector:
1. Press and hold the service brake pedal while the engine is running.
2. Select the appropriate drive gear.
3. Push and hold the yellow, dash-mounted parking brake knob until the
parking brake light turns off, then release.
If your vehicle is equipped with a manual transmission:
1. Press and hold the service brake pedal while the engine is running.
2. Press and hold the clutch pedal.
3. Select the appropriate drive gear.
4. Push and hold the yellow, dash-mounted parking brake knob until the
parking brake light turns off, then release.
Parking Brake Light Illumination Due to Low Air Pressure
If the air pressure becomes too low at any time during vehicle operation,
the parking brake may apply and the parking brake light turns on.
If the parking brake applies due to low air pressure, immediate service is
required to the parking brake system.
Parking Brake Warning System
If the parking brake light blinks and a tone sounds when pulling the
yellow control knob out, this indicates the parking brake is not
functioning properly. Seek service for the parking brake immediately.
With the ignition key not in the run position:
•A tone sounds if the parking brake remains released (or in an
unknown state). The tone stops in approximately eight minutes or
until the parking brake is applied. Seek service for the parking brake
immediately.
Diesel engines:Parking brake light operation (the light only works
when the ignition key is in the run position):
•On:Parking brake applied.
•Off:Parking brake released and no faults or malfunctions.
•Blink and tone:Parking brake released (or in an unknown state)
and faults or malfunctions exist.
150Brakes
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
Canadian_French(fr_can)